Stacking devices for cutting presses



Oct. 22, 1968 D. F. CREFFIELD STACKING DEVICES FOR CUTTING PRESSES 2 Sheets-Sheet 1 Filed Nov. 22, 1966 R w Mn 0mm 3 mm? x F @i mm b 11 m W0 Q W3 3 R DB o \w 1 Q M 1 06L 1968 D. F. CREFFIELD 3,40

STACKING DEVICES FOR CUTTING PRESSES Filed Nov. 22, 1966 2 Sheets-Sheet 2 Fig.2

35423 5; 50 39L J6 E 45 1 55 s A 2 E0 United States Patent 3,406,602 STACKING DEVICES FOR CUTTING PRESSES David F. Creffield, Bristol, England, assignor to United Shoe Machinery Corporation, Flemington, N.J., and Boston, Mass., a corporation of New Jersey Filed Nov. 22, 1966, Ser. No. 596,319 Claims priority, application Great Britain, Dec. 2, 1965, 51,140/ 65 6 Claims. (Cl. 83-92) This invention relates to improvements in or relating to the cutting of sheet material and more particularly to improvements in apparatus useful in cooperation with a cutting press for stacking cut portions of sheet material.

Cutting sheet material by means of presses which comprise a beam and a bed mounted for relative movement of approach and separation is a common operation. When, however, it is desired to repeatedly cut pieces from a supply, e.g., a roll or rolls, of sheet material, it is desirable, in order to achieve rapidity of operation, to provide for automatic feeding of the sheet material to be cut into the press and of the cut material out of the press. Devices for achieving this are often complex and expensive.

There is described in US. patent application Ser. No. 525,923 filed Feb. 8, 1966, now Patent No. 3,368,435, in the name of John S. Bastable, apparatus for use in cutting sheet material from a supply of indefinite length comprising a press having a beam mounted for movement relative to a bed, the beam comprising a rearward extension, a friction pad extending over an under-surface of the beam and extension, cutting means in the form of a die mounted on the beam and extending through the pad, a feed table arranged to move between a retracted position, in which an outfeed portion of the table is positioned between the beam and bed, and an advanced position in which an infeed portion of the table is positioned between the beam and bed and the outfeed portion is positioned beneath the extension, means for clamping sheet material against the table, and a stacking device to which the outfeed portion of the feed table is arranged to feed portions of the sheet material which have been cut from the supply thereof.

The present invention is illustrated as embodied in a cutting press having a beam and a bed in which the bed is movable toward and away from the beam, but it will be understood that the invention is not limited to embodiment in such a press.

It is one of the various objects of the present invention to provide in cutting presses organized as described above with a beam and bed mounted for relative movement and a feed table arranged to move between retracted and advanced positions, an improved stacking device for receiving cut portions of sheet material. To this end and in accordance with a feature of the present invention, there is provided in apparatus of the foregoing type an improved stacking device to which cut parts of sheet material are fed successively comprising a stacking table mounted for heightwise movement relative to the feed table, actuating means connecting the stacking table, the beam and the bed whereby, when movement of approach of the beam and bed is effected, the stacking table is raised to bring the upper surface thereof, or the upper surface of a stack of out parts supported thereon, into engagement with the under surface of the feed table. The actuating means has associated therewith adjusting means operative when the upward movement of the stacking table is stopped by engagement with the feed table to cause further movement of the actuating means to effect a non-resilient yielding of an element of the adjusting means so that as out parts are fed successively onto the stacking table in successive cycles of operation, the uppermost position of the stacking table is progressively lowered.

Other features and advantages of the invention will best be understood from the following description taken together with the accompanying drawings in which:

FIG. 1 is a side elevation, partly in section and with parts broken away of a cutting press embodying the present invention;

FIG. 2 is a plan view, partly in section and with parts broken away of apparatus shown in FIG. 1, and

FIG. 3 is a fragmentary view in end elevation of the apparatus shown in FIG. 1 viewed from left to right of said figure.

Referring now to FIGS. 1 to 3, the illustrative apparatus comprises a feed table 2, a cutting press generally designated 4 and the illustrative stacking device generally designated 6.

The press 4 comprises a base (not shown), a bed 8 and a beam 10; the bed is mounted for movement towards and away from the beam, which is fixed, under the action of a toggle arrangement 12 operated by a hydraulic motor 14. The toggle and motor are illustrated diagrammatically. The beam 10 is provided with suitable means generally designated 30 to clamp a die D against the undersurface of the beam.

The beam 10 is also provided with a rearward extension in the form of two arms 34 spaced apart from one another and supporting a carrier bar 36, the position of the carrier bar being adjustable lengthwise of the arms. Yieldingly mounted on the carrier bar 36 for movement heightwise thereof and spring-urged downwardly relative thereto is a clamping bar 38 which is arranged, when a cut portion of sheet material is fed beneath the rearward extension of the beam 10 by the feed table 2, to clamp the sheet material against the feed table. Also yieldingly mounted on the carrier bar 36 and spring-urged down- Wardly relative thereto is a separator bar 40.

The feed table 2 comprises a hardened steel plate having a polished upper surface. The table is supported on rolls 42 which run in guideways 44 secured at either side of the bed 8 and extending forwardly and rearwardly thereof, the feed table being reciprocated along the guideways 44 by pneumatic means (not shown) between an advanced position shown in FIG. 1 in which an outfeed portion 19 is under the rearward extension of the beam and an infeed portion 21 is between the beam and the bed and a retracted position in which the outfeed portion 19 is between the beam and the bed, the pneumatic means being adjustable so as to enable the amount of movement of the feed table to be varied according to the size of die being used. At its forward end portion the feed table is provided with a pneumatically operated clamping bar (not shown but corresponding to the clamping bar 20 of the apparatus shown in the hereinbefore mentioned application) which clamps the sheet material against the feed table when the latter is advanced to draw the material from the source of supply, e.g. a roll, but which is released prior to the feed table moving to its retracted position.

The illustrative stacking device 6, which is located beneath the rearward extension of the beam 10 of the press 4, comprises a stacking table 48 supported on a carriage 50 which is movable heightwise of a vertical column 52 mounted on a bracket 54 secured at the rearward face of the bed 8 of the press 4, the carriage being provided with two sets of four rolls 56 arranged to run on tracks provided by two ribs 58 formed one at either side of the column. The column 52 also houses a hydraulic cylinder 60 in which a piston 61 is movable heightwise, a piston rod 62 projecting upwardly therefrom and carrying at its upper end portion a sprocket 64 over which a chain 66 extends. One end of the chain is secured to the carriage 50 and the other end to the base of the press 4. Thus when in operation the bed 8 of the press is raised towards the beam 10, actuating means, interconnecting the beam, the bed and the stacking table and comprising the chain 66 secured to the press base, is operative to raise the stacking table 48 toward the outfeed portion 19 of the feed table 2.

Supported on the top of the column 52 is a guard 68 which prevents sheet material S laid on the stacking table 48 from becoming entangled with the chain 66. The upper surface of the stacking table 48 is covered with a sheet 70 of a flexible foam material.

Means for adjusting the height of the stacking table independently of the relative movement of the beam and the bed comprises the piston rod 62 which is extensible to increase the length of the upper chain bight and thus elfectively to shorten the chain to adjust the position of the stacking table for a given cyclical position of the beam and the bed. Power means facilitates raising the table in such adjustment. Thus oil under pressure from a pump P is admitted from a reservoir 80 to the lower end of the hydraulic cylinder 60 by operation of a manually operable valve 82 to cause the piston rod 62, and thus, through the sprocket 64 and chain 66, the stacking table 48, to be raised to bring the upper surface thereof immediately beneath the feed table 2 when the latter is in its advanced position. The ratio between the distance moved on the one hand by the stacking table and on the other by the piston rod is 2: 1. Thus in order to accommodate a stack of cut parts of sheet material twenty four inches deep for example, a twelve inch cylinder stroke only is required. a

In operation sheet material S is fed from a roll (not shown) supported in front of the press. At the beginning of each cycle of operation the bed 8 of the press 4, and thus also the stacking table 48, is in a lowered position and the feed table 2 in its retracted position with the outfeed portion 19 thereof between the beam and the bed 8 of the press. Sheet material S extending from the roll is clamped against the feed table by means of the clamping bar previously referred to, arranged at the forward end portion thereof and a cut portion S of sheet material lies on the outfeed portion of the feed table.

The feed table is then caused to move to its advanced position in which the infeed portion thereof is between the beam and bed of the press and the outfeed portion above the illustrative stacking device and beneath the rearward extension of the beam (as shown in FIG. 1).

The bed 8 of the press is then raised, the die D secured on the beam thus cutting a further portion S" (not shown) from the sheet material; in addition, the cut portion S on the outfeed portion of the feed table is pressed against the clamping bar 38 and the separator bar 40 which are thus raised a limited amount against the action of their springs. At the same time the illustrative stacking device 6 is raised together with the bed 8 and in addition the stacking table 48 is raised relative to the bed to cause the upper surface of the stacking table to press against the under-surface of the feed table 2.

After cutting of the sheet material has been effected, the bed 8 moves downwardly slightly to relieve the pressure and the clamping bar at the forward end of the feed table releases its clamping action on the sheet material. Thereafter while the cut portion S is held in position by the clamping and separator bars 38, 40 and the cut portion S" by the die D, the feed table 2 is moved again to its retracted position, the friction between the feed table on the one hand and the sheet material and cut portions on the other being sufficiently low for these to be undisturbed by movement of the feed table. As the feed table moves, the cut portion S is deposited on the upper surface of the stacking table 48. The position of the carrier bar 36 is so adjusted that when the feed table reaches its retracted position the clamping bar 38 is just clear of the cut portion S of the sheet material and thus is still clamping the cut portion S" against the feed table; the feed table has, however, moved from beneath the separator bar 40 which is thus urged downwardly by the action of its springs to ensure that the cut portion S is completely separated from the cut portion S" as it is laid on the stacking table. The separator bar is mounted in such a manner that, when in its lower position, it is inclined at a small angle to the horizontal, i.e. to the feed table transversely thereof; thus, when it is caused to separate the cut portion S as aforesaid, it acts progressively from one side of the cut portion to the other.

When the feed table has reached its retracted position, the bed 8 is lowered again and the clamping bar at the forward end portion of the feed table again clamps the sheet material against the feed table.

In subsequent cycles of operation of the illustrative assembly, the stacking table 48 of the illustrative stacking device 6 is so arranged that when the bed 8 is raised as aforesaid, the upper surface of the stack of cut portions of sheet material laid thereon is pressed against the undersurface of the feed table. Each successive cut portion of sheet material laid on the stacking table increases the depth of the stack thereon and thus in each successive cycel of operation the limit of upward movement of the stacking table is progressively lowered relative to the feed table by the thickness of one cut portion. The amount of upward movement of the column 52 on the other hand remains constant in each cycle of operation. Thus when the upper surface of the stack of cut portions of sheet material supported on the stacking table is pressed against the under-surface of the feed table and upward movement of the stacking table is thus arrested, the piston rod 62 and the piston yield downwardly relative to the cylinder 60 against the hydraulic pressure applied to the piston, fluid being forced down from the lower end of the cylinder 60 through a relief valve 84 to the reservoir whereby the yielding is non-resilient. The distance through which the piston rod so moves is half the distance by which the limit of upward movement of the stacking table is lowered, viz. half the thickness of one cut portion of sheet material.

When the stacking table 48 reaches its lowermost position, i.e. when it is fully loaded, operation of the illustrative assembly is brought to a halt; the stack is then removed and the valve 82 is operated to bring the stacking table again to its uppermost position.

The die D is so constructed and the assembly is so arranged that cross scrap, i.e. scrap extending across the width of the sheet material, is avoided. Scrap formed along the edges of the sheet material is removed from the cut portions along channels 72 provided one at either side of the bed 8 of the press and is collected in containers (not shown).

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a cutting press having a bed, a beam provided with a rearward extension, said beam and said bed being mounted for relative movement of approach and separation in cutting strokes, power means for effecting such movement, cutting means mounted on the beam for cutting sheet material -fed between said beam and said bed, a feed table arranged to move between a retracted position in which an outfeed portion of the table is positioned between the beam and the bed and an advanced position in which an infeed portion of the table is positioned between the beam and the bed and the outfeed portion is positioned under said rearward extension, means for clamping sheet material to the table when it is moved from its retracted position to its advanced position, and means mounted on said rearward extension for restraining the sheet material from movement with said table toward its retracted position, in combination therewith, a stacking table mounted for vertical movement toward and away from the underside of the outfeed portion of said feed table in its advanced position, actuating means connecting said stack-ing table, said beam and said bed for moving said stacking table with relative movement of said beam and said bed to raise said stacking table toward the feed table during relative movement of approach of said beam and said bed, and adjusting means associated with said connecting means and having an element thereof movable for varying the vertical position of said stacking table independently of said relative movement of the beam and the bed whereby to establish a relation of the position of the stacking table in which relative movement of approach of said beam and said bed is Operative to raise said table until stopped by engagement with the outfeed portion of said feed table, said adjusting means including means for providing a substantially non-resilient yielding of said element with continued relative movement of approach of the beam and the bed after such stoppage, whereby, as the height of out work parts on the stacking table increases, the vertical position of the table, at the time of such stoppage, lowers to maintain a receiving surface of uniform height.

2. Apparatus as defined in claim 1 and additionally including in said adjusting means power means for moving said element to adjust the position of said stacking table upwardly whereby it may be returned to its uppermost position.

3. Apparatus as defined in claim 2 wherein said power means comprises a hydraulic motor.

4. Apparatus as defined in claim 3 wherein the means for providing a substantially nonresilient yielding of the element comprises a relief valve connected to the hydraulic motor for exhausting pressure fluid therefrom.

5. Apparatus as defined in claim 1 and additionally comprising a separating member mounted on said rearward extension adjacent the clamping means, said separating member extending transversely of said feed table and being operative after movement of said table to its retracted position to move downwardly relative to the clamping means to separate a out part of sheet material from the remainder.

6. Apparatus as defined in claim 5 wherein said separating member has spring means urging it downwardly and is so arranged that, in operation, it operates progressively from one side of the sheet material to the other.

References Cited UNITED STATES PATENTS 2,958,431 11/1960 Curtenius 83-91 X 2,999,409 9/1961 Gollwitzer 8391 3,203,288 8/ 1965 Blumer 83-92 WILLIAM S. LAWSON, Primary Examiner. 

1. IN A CUTTING PRESS HAVING A BED, A BEAM PROVIDED WITH A REARWARD EXTENSION, SAID BEAM AND SAID BED BEING MOUNTED FOR RELATIVE MOVEMENT OF APPROACH AND SEPARATION IN CUTTING STROKES, POWER MEANS FOR EFFECTING SUCH MOVEMENT, CUTTING MEANS MOUNTED ON THE BEAM FOR CUTTING SHEET MATERIAL FED BETWEEN SAID BEAM AND SAID BED, A FEED TABLE ARRANGED TO MOVE BETWEEN A RETRACTED POSITION IN WHICH AN OUTFEED PORTION OF THE TABLE IS POSITIONED BETWEEN THE BEAM AND THE BED AND AN ADVANCED POSITION IN WHICH AN INFEED PORTION OF THE TABLE IS POSITIONED BETWEEN THE BEAM AND THE BED AND THE OUTFEED PORTION IS POSITIONED UNDER SAID REARWARD EXTENDION, MEANS FOR CLAMPING SHEET MATERIAL TO THE TABLE WHEN IT IS MOVED FROM ITS RETRACTED POSITION TO ITS ADVANCED POSITION, AND MEANS MOUNTED ON SAID REARWARD EXTENSION FOR RESTRAINING THE SHEET MATERIAL FROM MOVEMENT WITH SAID TABLE TOWARD ITS RETRACTED POSITION, IN COMBINATION THEREWITH, A STACKING TABLE MOUNTED FOR VERTICAL MOVEMENT TOWARD AND AWAY FROM THE UNDERSIDE OF THE OUTFEED PORTION OF SAID FEED TABLE IN ITS ADVANCED POSITION, ACTUATING MEANS CONNECTING SAID STACKING TABLE, SAID BEAM AND SAID BED FOR MOVING SAID STACKING TABLE WITH RELATIVE MOVEMENT OF SAID BEAM AND SAID BED TO RAISE SAID STACKING TABLE TOWARD THE FEED TABLE DURING RELATIVE MOVEMENT OF APPROACH OF SAID BEAM AND SAID BED, AND ADJUSTING MEANS ASSOCIATED WITH SAID CONNECTING MEANS AND HAVING AN ELEMENT ASSOCIATED MOVABLE FOR VARYING THE VERTICAL POSITION OF SAID STACKING TABLE INDEPENDENTLY OF SAID RELATIVE MOVEMENT OF THE BEAM AND THE BED WHEREBY TO ESTABLISH A RELATION OF THE POSITION OF THE STACKING TABLE IN WHICH RELATIVE MOVEMENT OF APPROACH OF SAID BEAM AND SAID BED IS OPERATIVE TO RAISE SAID TABLE UNTIL STOPPED BY ENGAGEMENT WITH THE OUTFEED PORTION OF SAID FEED TABLE, SAID ADJUSTING MEANS INCLUDING MEANS FOR PROVIDING A SUBSTANTIALLY NON-RESILIENT YIELDING OF SAID ELEMENT WITH CONTINUED RELATIVE MOVEMENT OF APPROACH OF THE BEAM AND THE BED AFTER SUCH STOPPAGE, WHEREBY, AS THE HEIGHT OF CUT WORK PARTS ON THE STACKING TABLE INCREASES, THE VERTICAL POSITION OF THE TABLE, AT THE TIME OF SUCH STOPPAGE, LOWERS TO MAINTAIN A RECEIVING SURFACE OF UNIFORM HEIGHT. 